Vehicle drive axle gearing



Sept. 17, 1946.7

M. B. MORGAN VEHICLE DRIVE AXLE GEARING Filed Sept. 8, 1942 2 Sheets-Sheet 1 Ma 17? en 5. {Marya/P Sept. 17-, 1946. M. B. MORGAN VEHICLE DRIVE AXLE GEARING Filed Sept. 8, 1942 2 Sheets-Sheet 2 Mai/7 ew 5. Marga/2 Jihad wyxyywnam Patented Sept. 17, 1946 VEHICLE DRIVE AXLE GEARING Mathew B. Morgan, Detroit, Mich., assignor to The Timken-Detroit Axle Company, Detroit, Mich., a corporation of Ohio Application September 8, 1942, Serial No. 457,654

3 Claims. (01. 74-326) 4 This invention relates to automotive vehicles and" is more particularly concerned with such vehicles having front and rear drive axles.

Heavy duty automotive vehicles wherein the engine is connected to drive both front and rear axles have recently been developed Widely espensive drive arrangements between the enginedriven propeller shaft and the front and rear axles which eliminates the usual transfer case hitherto considered necessary in such constructihs.. The invention is especially applicable to heavy duty vehicles having low gear ratio drive and requiring double reduction axles at front and rear.

It is a major object of my invention to provide novel mechanism for driving the front and rear axles of an automotive vehicle.

It is a further object of the invention to provide novel drive mechanism for driving all the axles of a heavy duty automotive vehicle having more than two drive axles.

A further object of the invention is to provide a novel double reduction drive mechanism for driving the front and rear axles of a heavy duty automotive vehicle which eliminates the usual transfer case.

A further object of the invention is to provide assembly.

A further important object of the invention is to provide a double reduction drive mechanism for driving at least two axles of a heavy duty vehicle in which the speed reduction gearing for both-0f the axles is disposed within the housing of one of them, which mechanism includes a countershaft extending between the two axles to drive them in synchronism.

Further objects of the invention will presently appear as the description proceeds in connection with the appended claims and the annexed drawings in which;

Figure 1 is a diagrammatic top plan view of a three axle vehicle embodying my novel front and rear axle drive arrangement;

Figure 2 is a Figure 1; i

Figure 3 is a top plan view partlyin section illustrating details of the change speed double reduction gearing for driving the front and the forward rear axles in the vehicle of Figures 1 and 2.

Referring to Figure l, a vehicle chassis II is supported at its forward end by a front drive axle I? provided at opposite ends with the usual dirigible Wheels (3 and formed intermediate its ends with a suitable difierential housing M. An internal combustion engine I5 of the usual type (shown in dotted lines in Figure l) is'mounted. on the front end of framel I.

The rear end of frame H is supported by spaced rear drive axles l6 and IT which are supported at opposite ends by dual wheel sets 18 and I9, respectively. Axles I6 and H are interconnected by suitable springs 2| which in turn are pivotally connected to frame H at their mid points on trunnions 22. The suspension between axles l6 and I1 and frame I I may comprise any suitable tandem axle suspension without departing from the spirit of the invention.

Axles l6 and I! are formed with identical differential housing 23 and 24, one of which is illustrated in detail in Figure 3. An engine-driven propeller shaft 25 extends from engine iii to the forward rear'axle differential housing 23 where it is connected by suitable change speed double reduction aring to a drive or transfer shaft 26 which drives axle I6 and extends forwardly from diiierential housing 23 to drive the diiferential Within housing [4 on the front axle. Propeller shaft 25 (Figures 1 and 2) extends through differential housing 23 and i provided with an extension 21 leading to the rear differential housing 24 wherein it drivesthe rearmost axle through variable speed double reduction gearing similar to that within housing 23.

The invention may be applied to a two axle vehicle simply by eliminating axle ll of Figures 1 and 2 and terminating the propeller shaft at axle l6. V

In Figures 1 and 2 drive shaft 26 is shown as side elevation of the vehicle of i Referring to Figure 3, differential housing 23 is preferably internally divided by a transverse wall 29 into a differential chamber 3}, anda forward gear chamber 32, chamber 32 being disposed forwardly of the housing in the direction, of the front axle. Front wall 330i gear chamber 32 is removable, being bolted or similarly fastened jv to the housing. Housing 23 is longitudinally split at one side and the housing sections are removably fastened together as by bolts 34. This construction affords convenient accessto the gearing within housing 23.

A propeller shaft section 35 extends longitudinally through housing 23 well above the differential gearing within chamber 3|. Shaft section 35 is supported at opposite ends in suitable antifriction bearings 36, and 31 in the rear wall of housing 23 and in wall 33, respectively. Shaft section 35 lies in the vertical plane containing propeller shaft 25 and extension 2'1, which plane preferably also contains the longitudinal centerline of the vehicle.

The opposite ends of shaft section 35 are flanged for convenient attachment to suitable universal joints (not shown) connecting it to shaft 25 and extension 21. V

Within chamber 32, spur gears 38 and 39 of different diameter and number of teeth are independently rotatably mounted on shaft 35. Gear 38 is rotatably mounted directly on the shaft, and gear 39 is in turn rotatably mounted on the rearwardly extended hub of gear 38. The rearwardly extended hub of gear 39 is supported by an anti-friction bearing 4| in a suitable aperture in wall 29 thus providing an intermediate support for shaft section 35.

The telescoping hubs of gears 38 and 39 extend through apertured wall 29 into chamber 3! and are formed at their ends with spaced toothed clutch jaws 42 and 43, respectively.

Within chamber 3|, a clutch collar 44 is slidably but non-rotatably mounted on shaft 35 as by spline 45, and clutch collar 44 is provided with a toothed clutch jaw 46 interposed between clutch jaws 42 and 43 of the spur gears. A suitable shifter mechanism actuated by a lever within the drivers compartment in the vehicle (not shown) is attached in a conventionalumanner for sliding clutch collar 44 back and forth to mesh clutch jaw 45 with either of jaws 42 or 43 to drive either of. gears 38 or 39, respectively, from the shaft. I

A rotatable. drive shaft section 47 is supported intermediate its ends by an anti-friction bearing 48 in an aperture in wall 29 and is supported at opposite ends by suitable bearings 49 and 51 in front wall 33 and a stationary internal wall within housing 23. Within chamber 32 shaft 41 has non-rotatably secured thereto a pair of. spur gears 52. and 53constantly meshed with gears 38 and 39 on shaft 33.

than the gears 38 and 39 with which they are reduction in the drive; that is, the shaft 41 may be driven at either of two lower speeds than the propeller shaft. Drive shaft section 41 is parallel to propeller shaft section 35 but is displaced laterally and downwardly therefrom to locate the axis of shaft 4! in the horizontal plane containing the axis of axle l6 and provide for plenty of roadclearance between shafts 25 and 26 which rotate in opposite directions.

Within chamber 31 and between bearings 48 and 51, shaft 41 carries a relatively small hypoid bevel gear 54 which is meshed with the usual hypoid bevel gear 55of the differential mechanism of the live axle shafting within axle I 6.

Since the differential mechanism and the remaining live axle construction within axle 16 may be of conventional construction, no further description thereof is necessary. Since gear 54 is substantially smaller than gear 55 this effects a second reduction in drive between the propeller shaft and the live axle.

At its front end shaft 4! extends through wall 33 and is flanged for attachment to a universal joint (not shown) on the rear end of drive shaft 26. The front end of shaft 26 is similarly universallyattached to a flange on a stub shaft 55 supported at its rear end by spaced bearings 51 and 58 in an apertured boss extending rearwardly from housing It. Stub shaft 56 is also located with its axis in the horizontal plane containing the axis of axle l2. Within housing l4, shaft 55 has its front end supported in a suitable bearing 53 on an internal wall of housing l4. Between bearings 58 and 59, shaft 56 has secured thereto a hypoid bevel gear SI of the same size as gear 54. ferential hypoid bevel gear 62 of the same size as differential gear 55 in rear axle Hi. The remaining live axle construction within axle i2 is of conventional construction and preferably substantially the same as in axle l6.

, Within differential housing 24, the live axle shafting of axle ll is connected to propeller shaft extension 21 by a variable speed double reduction system of spur gears and hypoid bevel gears in the, same manner as shown within housing 23 in Figure 3. The driver control for clutch collar The only difference is that the front end of drive shaft section 47 within housing 24 terminates "and is covered by an end cap at bearing 49 and the rear end of propeller shaft section 35 within the housing 24 terminates and is covered by an end cap at bearing 36. Similarly in'a two axle vehicle according to the invention, propeller shaft section 35 in housing 23 would be terminated and capped at bearing 35.

My invention provides a variable speed double reduction drive for both the front and rear axles of two or three axle vehicle without the employment of an expensive transfer case mechanism. In the usual transfer case design, when it is desired to provide a double reduction change drive at both front and rear axles,'it is necessary to provide two sets of reduction gears at thefront axle. The necessity for such is eliminated in my "design since the change speed mechanism on housing 23 serves as the first reduction in the drive for both axles l2 and l6. Because of this I am able to use a smaller axlehousing at the front drive axle.

Since the bevel gear drives at 54, 55 in axles Gear 51 is meshed with a difl6 and I1 and GI, 62 in axle l2 comprise the second drive reduction, their drive ratio may be relatively high, approximately in the range of 3 or 3 to 1 being preferred. In this patent the term double reduction relates to two drive reductions regardless of the drive ratio of those reductions.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is:

1. In a vehicle, a drive axle, a motor driven propeller shaft section disposed substantially at right angles to said axle and extending forwardly and rearwardly thereof, axle drive mechanism including a drive shaft at one side of the axle in substantially parallel relation with one end of said propeller shaft section, housing structure for said axle drive mechanism supported on the axle and journalling the other end of said propeller shaft section at the opposite side of the axle, said housing structure having a lateral extension providing a gear chamber, in opposite side Wall of which chamber said drive shaft and propeller shaft section are journalled, gearing within said chamber for transmitting power at reduced speed from said propeller shaft section to the drive shaft including change speed gears loosely mounted on said propeller shaft section, and a manually shiftable member keyed to said propeller shaft section Within the housing to selectively connect said gears in driving relation with said propeller shaft section.

2. In a vehicle drive axle, a differential housing, a differential unit therein having a driving gear, a, comparatively shallow gear chamber rigidly fixed to one side of said differential housing, a motor driven propeller shaft and a differential drive shaft mounted in opposite side walls of the gear chamber and positioned in relatively difierent-vertical and horizontal planes with the axes of said shafts spaced from the radial plane of the differential driving gear at opposite sides thereof, a pinion on said drive shaft meshed with said differential driving gear, a pair of closely juxtaposed speed reducing gears fixed to said drive shaft within the gear chamber, a complementary pair of gears loosely mounted on the propeller shaft and in constant mesh with the respective speed reducing gears, and means constantly drive connected to said propeller shaft and located externally of said gear chamber for selectively establishing a driving connection between said complementary pair of gears and the propeller shaft.

3. The vehicle drive mechanism defined in claim 2, in which said gear selecting means includes a shiftable clutch member on the propeller shaft within the differential housing.

MATHEW B. MORGAN. 

